A bit messy game. At one point you get to choose which level you want, but it doesn't change the main story of the game. After I beat the game I played through them: 01:01:01 Missions 4 and 7. Also I couldn't find out how to reach mission 11 (According to one FAQ on GameFAQs, it doesn't exist). Also I got the mission 8 briefing after I beat that mission. Like I sadi - a mess.